# RSC-006: remote resource not allowed, how to fix it

Source: https://epubcc.com/epubcheck/rsc-006/ (updated 2026-11-04)

EPUBCheck RSC-006 is an error message: “Remote resource reference is not allowed in this context; resource "…" must be located in the EPUB container.” A resource is loaded from the web in a place where EPUB requires it to be inside the EPUB file. Only audio, video, fonts and resources fetched by scripts may stay remote; everything else must be in the container so the book works offline.

- Official message (EPUBCheck 5.4.0): Remote resource reference is not allowed in this context; resource "%1$s" must be located in the EPUB container.
- Default severity: Error

## Typical causes

- Images or stylesheets referenced by an http or https URL instead of a file in the book.
- Content copied from a web page with its absolute image URLs.

## How to fix it

1. Download the resource, add it to the EPUB and the manifest, and reference it by a relative path.
2. EPUB 3 allows remote audio, video and fonts; those need the remote-resources property on the manifest item of the document that uses them.
3. Validate again.

## When it's not this

An ordinary hyperlink to a website is allowed; RSC-006 is about resources the page loads, such as images.

## Sources

- EPUB 3.3, §3.6 Resource locations: https://www.w3.org/TR/epub-33/#sec-resource-locations (read 2026-11-04)

Message text and severity: EPUBCheck (W3C, BSD-3-Clause). Explanation: EpubCC.